Wildwood, my apologies. Clearly, I should have clarified the points I made.
The point I was making was that NOT ALL monitors are released from the factories dead pixel free. The premium range monitors are tested and if they don't have a single dead pixel, they are sold as the top grade. If the manufacturing line only produces top grade monitors, the displays on those with dead pixels present are either scrapped (in the case of Sony and a few others) or graded to a lower grade depending on the number of dead pixels present.
If your prepared to pay for a monitor that's completely dead pixel free that is what you'll get and the warranty will reflect that. Unless the monitor is in this top grade, dead pixels are excluded from the warranty.
As an example, if you send a bog-standard monitor in for servicing within the twelve month warranty with say, a dead power supply, the monitor will be returned to you in a working condition. You can neither ask nor expect the service agent to fit a new display on the basis of it having dead pixels. They are simply not covered by the warranty. In the case of a premium monitor, the display would be replaced.
The bottom line is that if you've bought a bog-standard monitor and it's without a single dead pixel, count yourself very lucky. Most bog-standard monitors are not like that and if you want to exchange it, it's up to the goodwill of the retailer.
I have dealings with a well known monitor manufacturer that produces millions of them per year. They've admitted to me that quality control surveys have shown that in their basic range of monitors, they churn out no more than around 50 monitors annually that are completely dead pixel free.